postgresql/src/backend/parser/scansup.c

/*-------------------------------------------------------------------------
 *
 * scansup.c--
 *	  support routines for the lex/flex scanner, used by both the normal
 * backend as well as the bootstrap backend
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/backend/parser/scansup.c,v 1.8 1997/11/25 22:05:55 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */

#include "config.h"

#include <ctype.h>
#include <string.h>
#include "postgres.h"
#include "miscadmin.h"
#include "utils/elog.h"
#include "parser/scansup.h"

/* ----------------
 *		scanstr
 *
 * if the string passed in has escaped codes, map the escape codes to actual
 * chars
 *
 * also, remove leading and ending quotes '"' if any
 *
 * the string passed in must be non-null
 *
 * the string returned is a pointer to static storage and should NOT
 * be freed by the CALLER.
 * ----------------
 */

char	   *
scanstr(char *s)
{
	static char newStr[MAX_PARSE_BUFFER];
	int			len,
				i,
				j;

	if (s == NULL || s[0] == '\0')
		return s;

	len = strlen(s);

	for (i = 0, j = 0; i < len; i++)
	{
		if (s[i] == '\'')
		{
			i = i + 1;
			if (s[i] == '\'')
				newStr[j] = '\'';
		}
		else
		{
			if (s[i] == '\\')
			{
				i = i + 1;
				switch (s[i])
				{
					case '\\':
						newStr[j] = '\\';
						break;
					case 'b':
						newStr[j] = '\b';
						break;
					case 'f':
						newStr[j] = '\f';
						break;
					case 'n':
						newStr[j] = '\n';
						break;
					case 'r':
						newStr[j] = '\r';
						break;
					case 't':
						newStr[j] = '\t';
						break;
					case '"':
						newStr[j] = '"';
						break;
					case '\'':
						newStr[j] = '\'';
						break;
					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
					case '5':
					case '6':
					case '7':
						{
							char		octal[4];
							int			k;
							long		octVal;

							for (k = 0;
							 s[i + k] >= '0' && s[i + k] <= '7' && k < 3;
								 k++)
								octal[k] = s[i + k];
							i += k - 1;
							octal[3] = '\0';

							octVal = strtol(octal, 0, 8);
/*						elog (NOTICE, "octal = %s octVal = %d, %od", octal, octVal, octVal);*/
							if (octVal <= 0377)
							{
								newStr[j] = ((char) octVal);
								break;
							}
						}
					default:
						newStr[j] = s[i];
				}				/* switch */
			}					/* s[i] == '\\' */
			else
				newStr[j] = s[i];
		}
		j++;
	}
	newStr[j] = '\0';
	return newStr;
}